This year marks the centenary of the first two flights, by seaplane and landplane, around mainland Australia. The first began on 6 April 1924, when Wing Commander Stanley Goble and Flying Officer Ivor McIntyre set off from the RAAF base at Point Cook, Victoria, in a single-engine, open-cockpit, Fairey IIID seaplane, A10-3. On 19 May, after 44 days and 13,600 kilometres, they alighted at St Kilda beach, Victoria, to an enthusiastic welcome. The second round-Australia trip, this time in a landplane, was conducted by the Civil Aviation Branch of the Department of Defence to inspect air routes and to test the long-distance efficiency of the De Havilland D.H.50 aircraft. The crew of the aircraft, registered G-AUAB, comprised expedition leader Lt Col HC Brinsmead, pilot Captain EJ Jones and mechanic RH Buchanan. They departed Point Cook on 7 August and after 12,324 kilometres arrived back at Point Cook on 29 August.

This unique double-sided cover is a limited edition of 120. It features a numbered medallion, made of zinc alloy and finished in antique gold and antique silver, with a dual-sided spinning propeller, minimum weight 41g, maximum diameter 48mm, maximum thickness 4mm.